A simple method to recover the graphene-based chemi-resistor signal

Abstract

We present the development of a simple and fast method for restoring exhaust graphene-based chemi-resistors used for NO2 detection. Repeatedly exposing the devices to gases or to air for more than 2 days, an overall worsening of the sensing signal is observed; we hypothesized that the poisoning effect in both cases is caused by the exposure to NO2. Starting from this hypothesis and from the observation that NO2 is soluble in water, we performed a recovery method consisting in the dipping of exhaust devices into ultrapure water at 100 °C for 60 s. The device performances are compared with those obtained after the restoration is achieved using the typical annealing under vacuum method.